Journal of Animal Science

Effects of dietary protein level and amino acid supplementation on performance of mixed-parity lactating sows in a tropical humid climate

B. A. N. Silva*,**, J. Noblet***, J. L. Donzele**, R. F. M. Oliveira**, Y. Primot ****, J. L. Gourdine* and D. Renaudeau*

Abstarc :

Eighty-six mixed-parity Large White sows were used to determinethe effect of diets with reduced CP content or supplementedwith essential AA on 28-d lactation performance under humidtropical climatic conditions. This experiment was conductedin Guadeloupe (West French Indies, latitude 16°N, longitude61°W) between February 2007 and January 2008. Two seasonswere distinguished a posteriori from climatic measurement variablescontinuously recorded in the farrowing room. The average minimumand maximum ambient temperatures and average daily relativehumidity for the warm season were 20.5 and 28.2°C, and 93.8%,respectively. The corresponding values for the hot season were22.7 and 29.4°C, and 93.7%, respectively. The dietary experimentaltreatments were a normal protein diet (NP), a low protein diet(LP), and a NP diet (NP+) supplemented with essential AA. TheNP and LP diets supplied the same levels of standardized digestibleLys (i.e., 0.80 g/MJ of NE), and the NP+ diet supplied 0.95g/MJ of NE. No interaction between season and diet compositionwas noted on any response variable evaluated. The ADFI was decreased(P < 0.05) in the hot season (i.e., 3.69 vs. 4.72 kg) andtherefore decreased by 500 g per °C increase of ambienttemperature under high relative humidity conditions. The ADFItended to be greater with the LP and NP+ diets when comparedwith the NP treatment (i.e., +10%, P = 0.08). Litter BW gainand mean BW of piglets at weaning were greater (P < 0.05)during the warm season than during the hot season (2.3 vs. 1.8kg/d and 7.5 vs. 7.1 kg, respectively). Milk production andcomposition were not affected by dietary treatments but wereaffected by season (8.1 vs. 6.8 kg/d, for warm and hot seasons,respectively; P < 0.01). The sows fed LP and NP+ diets tendedto have decreased backfat thickness losses (3.3 and 3.8 mm,respectively; P > 0.08). In conclusion, the hot season inhumid tropical climates, which combines high levels of temperatureand humidity, has a pronounced negative impact on performanceof lactating sows. Diets with low CP content or supplementedwith essential AA can attenuate the effects of hot and humidseason by increasing ADFI in lactating sows.

Key Word :
feed intake, lactation, lysine, protein, sow, tropical climate

Volume 87, Number 12, December 2009